Door latch mechanism



Nov. 5, 1963 c. E. HAFSTAD 3,109,674

DOOR LATCH MECHANISM Filed Dec. 6 1961 Ha. I

INVENTOR. CARL E HAFSTAD AT T ORNEYS United States Patent 3,109,674 DOGRLATCH MECHANISM Carl E. Hafstad, 828 21st Ave. 5., Minneapolis, Minn.

Filed Dec. 6, 1961, Ser. No. 157,357

6 Claims. (Cl. 292-76) This invention relates generally to door latchmechanisms, and more particularly it relates to an improved and usefuldoor latch mechanism the latching action of which is generallyfrictional in character, but which is also provided with novel means forlocking the door to which said latch mechanism is secured by renderinginoperative the friction catch elements of said mechanism.

More specifically, this invention relates to and is somewhat in thenature of an improvement upon the disclosure of my previous UnitedStates Patent No. 3,012,803, entitled Friction Catch, issued December12, 1961. The friction catch mechanism comprising a pair of generallyparallel coil compression springs as disclosed in my above notedprevious application is unique in that the force required to open thedoor to which it is attached is materially greater than the forcerequired to close the door, and such friction catch is of obviousutility for many installations. However, said invention disclosed in myprevious application is not provided with positive locking means, andtherefore although the same may be opened only by the application of arelatively great force as compared with the amount of force required toclose the door, it is further desirable in certain installations toprovide a friction catch mechanism in which the same is provided withlocking means for preventing the accidental opening of the door, andwhich is also provided with positive locking means for use at certaintimes, such as at night.

In light of the above, an important object of this invention is theprovision of an improved door latch mechanism having the above notedfriction catch characteristics in combination means for positivelypreventing accidental opening of the door to which said door latch isattached, and also in combination with locking means for positivelylocking said door.

Another object of this invention is the provision of an improved doorlatch mechanism which may be easily opened from either side of the doorto which it is at tached merely by the application of a unidirectionalpushing or pulling force.

Another object of this invention is the provision of an improved doorlatch mechanism in which the above described means for positivelypreventing accidental opening of the door is easily and quickly avoidedmerely by the application of said unidirectional pushing or pullingopening force to the appropriate elements of said invention.

Other objects of this invention reside in the provision of an improveddoor latch mechanism which is extremely simple in construction, durableand strong throughout long periods of continued use, relativelyinexpensive to manufacture, simple and efiicient in its operation, andhighly efiicient in sustaining the above noted objects and purposes.

The above and still further objects of this invention will becomeapparent from the following detailed specification, appended claims andattached drawings.

Referring to the drawings wherein like reference characters indicatedlike parts or elements throughout the several views:

FIG. 1 is a view in side elevation of this invention as seen from aposition adjacent the free edge of the door member to which saidinvention is attached, some parts shown in section;

FIG. 2 is a view in section taken on the line 2-2 of 3,109,674 PatentedNov. 5, 1963 FIG. 1, and showing a substantial portion of this inventionin front elevation;

FIG. 3 is a view in section taken on the line 33 of FIG. 1, some partsbeing broken away, and this view showing my novel door latch mechanismin its closed door position, and with the positive locking: means ofthis invention shown in its locked position by full lines and also shownin its unlocked position by dotted lines;

16. 4 is a view in section corresponding generally to FIG. 3, butshowing my novel door latch .mechanism during initial opening movementof the door;

FIG. 5 is a view in section corresponding generally to FIGS. 3 and 4,but showing my novel door latch mechanism during final closing movementof the door;

FIG. 6 is a view in section taken substantially on the line 6-6 of FIG.3; and

FIG. 7 is a view in section taken on the line 77 of FIG. 2.

Referring with greater particularity to the drawings, the door member,represented generally by the reference letter A is movably mounted in ajarnb member, which is represented generally by the reference letter B.A conventional keeper element 1 is rigidly secured to the inner face bof the jamb member B, near the outer edge 0 thereof, by means of a pairof screws 2. This invention resides in the provision of an improved doorlatch mechanism, which is represented generally by the reference numeral3. Also, the inner face of the door member A is represented by thereference letter a, the outer face thereof by the reference letter d,and the, free edge of the door member A being represented by thereference letter e.

In accordance with present practices, the door latch mechanism 3comprises a rigid supporting housing, represented generally by thereference numeral 4, said supporting housing 4 including a front wall orfront plate portion '5, a side wall 6, a top wall 7, a bottom wall 8,and a pluralityof apertures for receiving elongated screws 9 for rigidlysecuring the supporting housing 4 to the inner face a of the door memberA. It is noted that the back of the supporting housing 4 is generallyopen, and the supporting housing 4 is also formed in a generallybifurcated manner at the outer side thereof so as to define spaced andalignable spring-carrying flanges 10. As shown, a pair of elongated coilsprings 11, 12 are carried by the spaced flanges 10 of the supportinghousing 4 so as to dispose the respective end portions 13, 14 of thecoil springs 111, 12 in a fixed but spaced relationship with respect tothe door member A. It is noted that the respective end portions 13, '14of the coil springs '11, 12 are rigidly secured, as by welding orsoldering, in the respective positions shown particularly in thedrawings. The end portions 113 of the outermost coil spring 11 areengaged by generally arcuate and aligned end claw portions 15 of thespring-carrying flanges 10, and the end portions 14 of the generallyinwardly disposed coil spring 12 are engaged by generally intermediatelydisposed generally arcuate and aligned claw portions 16 of thespring-carrying flanges 10. With this arrangement, the coil springs 11,12, are disposed in general axial parallelism with one another, and saidcoil springs 11, 12 are positioned relative to the supporting housing 4in generally longitudinal engagement with one another and furtherarranged and adapted so that the generally outermost coil spring 11 isengaged by the keeper element 1 carried by the jamb member B duringinitial opening movement of the door member A with respect to said jambmember B and concerted lateral deflection is thereby imparted to both ofthe coil springs 11, 12 in the generally same lateral direction duringsaid initial opening movement of the door member A, this being shownparticularly in FIG. 4. Furthermore, the disposition of the coil springs11, 12 is such that lateral deflection in another direction is impartedonly to the generally outwardly disposed coil spring 11 during finalclosing movement of the door member A wit-h respect to the jamb memberB, as shown particularly in FIG. 5. i

In order to retain or restrain the coil-springs 11, 12 against undesireddeflection or displacement so as to prevent acoidental or undesiredopening of the door member A, means is provided to bear against thegenerally inwardly disposed coil spring 12, said means being referred toments described above, the push rod 18 is mounted for sliding movementsto a second position, shown in FIG. 4, wherein the collar element 25 isdisposed in spaced relationship to the front Wall of the supportinghousing 4 and also in spaced relationship to the coil spring 12 wherebyto permit deflection of the'coil springs 11, 12 by the keeper element 1and thereby permit opening movement of the door member A, as shownparticularly herein as a restraining member, represented generally by vthe reference numeral 17, and which is carried at least partially by thesupporting housing 4 in a manner which will be more particularlydescribed hereinafter. The restraining member 17 comprises an elongatedpush rod 18 which is mounted and guided in the door member A and thesupporting housing 4 for reciprocatory movements generally in itslongitudinal direction and in a direction generally transverse of thedoormember A. The outer end portion 19 of the push rod 18 projectsthrough the door member A and is slidably received within a mountingplate 20, and is also provided with an outer knob 21. The inner endportion 22 of the push rod 18 is sl-idably received within and projectsthrough an axially aligned aperture defined in the front wall 5 of thesupporting housing 4, and said inner end portion 22 of the push rod 18is also provided with an inner knob 23. With this arrangement, it isnoted that the knob-equipped outer end portion 19 of the push rod 18 isdisposed outwardly of the outer face. a of the door member A, and theknobequipped inner end portion 22 of the push rod 18 is disposedadjacent the outer side or outwardly of the front wall or front plateportion 5 of the supporting housing 4. It is noted that the elongatedscrews 9 which secure the supporting housing 4 to the door member A arereceived within screw threaded recesses defined by the mounting plate20, so as to secure the mounting plate in the supporting housing 4 onaligned opposite sides of the door member A, as shown particularly bydotted lines in FIG. 3 and also shown in FIG. 7.

The generally intermediate portion 24 of the push rod 18 receives acollar element 25, which is rigidly secured to said push rod 18 by meansof a diametrically extending cross pin 26, as shown particularly in FIG.3. The collar element 25 is positioned on the push rod 18 so as to bedisposed in the space between the front wall or plate portion 5 of thesupporting housing 4 and the inner face or side a of the door member A.The collar element 25, as shown in the drawings, is generallycylindrical in construc tion, however, it should be appreciated thatmany parametric configurations would be suitable. In accordance withthis invention, the push rod 18 and the collar element 25 carriedthereby is normally disposed in one position shown particularly in FIGS.3 and 5, wherein the collar element 25 is disposed adjacent thegenerally inter mediate portion of the generally inwardly disposed coilspring 12, and the collar element 25 when it is disposed in its saidnormal position is engaged by said coil spring 12 when the generallyoutwardly disposed coil spring 11 is engaged by the keeper element 1whereby to substantially prevent deflection of the coil springs 11, 12and thereby prevent opening movement of the door member A with respectto the jamb member B. With reference to FIG. 3, it is noted that whenthe push rod 18 and the collar element 25 carried thereby are disposedin said above described position wherein said collar element 25 isdisposed adjacent the inner surface of said front wall 5 of thesupporting housing 4 and also adjacent the coil spring 12, the doormember A cannot be opened without displacing the-collar element 25 sincesaid collar element 25 abuts against and prevents deflection ordisplacement of the coil springs 11, 12, and this of course may only beovercome by applying enough force to the door member A to completelydeform the coil springs 11, 12.

With the novel combination and arrangement of elein FIG. 4. It should beappreciated that the collar element 25 may be easily moved out of itsabove described restraining position to its said second position merelyby pushing on the inner knob 23 or pulling on the outer knob 21.provided for biasing the collar element 25 and hence the push rod 18toward the above described restraining position thereof, said yieldingmeans comprising a conical coiled compression spring 27 concentricallydisposed around said generally intermediate portion 24 of the push rod18and also disposed intermediate the inner face or side a of the doormember A and the collar element 25. Novel lock means is also provided incombination with the above described components of this invention forfixing the push rod 18 of the restraining member 17 in the saidrestraining position of' the collar element 25 whereby the door member Amay be locked in its closed position, shown particularly in FIGS. 3 and5. Said lock means comprises an annular recess 28 defined by the pushrod 18 and located generally adjacent the outer surface of the frontplate portion 5 of the supporting housing 4 when the collar element 25carried by said push rod 18 is disposed in its above noted restrainingposition. A slide element 29 provided with a slotted end portion 30which cooperates with said annular recess 28 and engages the same so asto prevent the above noted reciprocating or sliding movements of thepush rod 18. The slide element 29 is mounted for sliding movementswithin a guide track 31 defined by the front wall or front plate portion5 of the supporting housing 4, and the slide element 29 defines alaterally outwardly projecting end tab 32 for moving said slide elementinto and out of engagement with the recess 28 of the push rod 18.

Having specifically described this invention, the operation thereof isthought to be easily understandable from said description. Thisinvention has been thoroughly tested and found to be completelysatisfactory for the accomplishment of the above objects; and while Ihave shown and described above a preferred embodiment thereof in whichthe principles of the present invention have been incorporated, I wishit to be specifically understood that the same may be modified withoutdeparture from the scope and spirit of the appended claims.

What Iclaim is:

1. In a latch mechanism for latching a door member mounted for openingand closing movements relative to a cooperating jamb member, and inwhich said jamb member is provided with a rigidly mounted keeperelement, an improved friction catch, said improved friction catchcomprising: a

(a) a supporting housing rigidly secured to said door member, I

(b) a pair of elongated coil springs carried by said supporting housingin spaced relation to said jamb member with the respective end portionsof said coil springs fixedly disposed with respect to said'door member,

(c) said coil springs being disposed in general axial parallelism withone another,

(d) said coil springs being'positioned relative to said supportinghousing an generally longitudinal engagement with one another andfurther arranged and adapted so that one of said springs is engaged bysaid keeper element during initial opening movement of said door memberwith respect to said jamb member and concerted lateral deflection isthereby According to present practices, yielding means is a imparted toboth of said coil springs in the generally same lateral direction duringsaid movement,

(e) the disposition of said coil springs being such that lateraldeflection in another direction is imparted only to said one of saidsprings during final closing movement of said door member with re spectto said jamb member,

(f) a restraining member carried by said supporting housing forreciprocating movements in a direction generally transverse of said doormember and normally disposed in one position adjacent the generallyintermediate portion of the other of said coil springs generallyopposite said keeper element, said restraining member When in said oneposition being engaged by said other of said coil springs when said onecoil spring is engaged by the keeper element whereby to substantiallyprevent deflection of said coil springs and thereby prevent openingmovement of said door member with respect to said j-amb member, and

(g) said restraining member being reciprocally movable to anotherposition in spaced relationship to said other of said coil springswhereby to permit deflection of said coil springs by said keeper elementand thereby permit opening movement of said door member.

2. The structure defined in claim 1 in further combination with lockmeans for fixing said restraining member in its said one positionwhereby said door member may be locked in its closed position.

3. The structure defined in claim 1 in further combination with yieldingmeans biasing said restraining member toward its said one position. v

4. In a latch mechanism for latching a door member mounted for openingand closing movements relative to a cooperating jamb member, and inwhich said iamb member is provided with a rigidly mounted keeperelement, an improved friction catch, said improved friction catchcomprising:

(a) a supporting housing rigidly secured to one side of said door memberadjacent a free edge of said door member, said supporting housingincluding a plate portion disposed in spaced relationship to said oneside or the door member,

(b) a pair of elongated coil springs carried by said supporting housingin spaced relation to said jamb member with the respective end portionsof said coil springs fixedly disposed with respect to said door member,

(0) said coil springs being disposed in general axial parallelism withone another,

(d) said coil springs being positioned relative to said supportinghousing in generally longitudinal engagement with one another andfurther arranged and adapted so that one of said springs is engaged bysaid keeper element during initial opening movement of said door memberwith respect to said jamb member and concerted lateral deflection isthereby imparted to both of said coil springs in the generally samelateral direction during said movement,

(e) the disposition of said coil springs being such that lateraldeflection in another direction is imparted only to said one of saidsprings during final closing move ment of said door member with respectto said member,

(7) a restraining member carried by said supporting housing, saidrestraining member comprising:

(l) a push rod mounted and guided in said door member and saidsupporting housing for reciproeating movements generally in itslongitudinal direction and in a direction generally transverse of saiddoor member, said push rod having opposite end portions one of which isdisposed outwardly of said plate portion of said supporting house andthe other of which is disposed outwardly of the other side of said doormember,

(2) a collar element rigidly secured to an intermediate portion of saidpush rod and disposed in the space between said plate portion of saidsupporting housing and said one side of said door member, and

(3) said push rod being normally disposed in one position wherein saidcollar element carried thereby is disposed adjacent the generallyintermediate portion of the other of said coil springs generallyopposite said keeper element, said collar element of said push rod whensaid push rod is in said one position being engaged by said other ofsaid coil springs when said one coil spring is engaged by the keeperelement whereby to substantially prevent deflection or said coil springsand thereby prevent opening movement of said door member with respect tosaid jamb member, and

(g) said push rod being movable to another position wherein said collarelement thereof is disposed in spaced relationship to said other of saidcoil springs whereby to permit deflection of said coil springs by saidkeeper element and thereby permit opening movement of said door member.

5. The structure defined in claim 4 in further combination with lockmeans for fixing said push rod of said restraining member in its saidone position whereby said door member may be locked in its closedposition, said lock means comprising:

(a) a recess defined by said push rod and located generally adjacent theplate portion of said supporting housing when said push rod is in itssaid one position, and

(b) a slide element having an end portion adapted to engage said recessof said push rod and prevent said reciprocating movements thereof, saidslide element being mounted for sliding movement-s into and out ofengagement with said recess of said push rod.

6. The structure defined in claim 5 in further combination with yieldingmeans biasing said push rod of said restraining member toward its saidone position, said yielding mew-s comprising a coiled compression springconcentrically disposed around a generally intermediate portion of saidpush rod and also disposed intermediate said one side of said doormember and the collar element of said restraining member.

References Cited in the tile of this patent UNITED STATES PATENTS1,023,014 Hanson Apr. 9, 1912 2,036,154 Littledale Mar. 31, 19362,931,675 Coulson Apr. 5, 1960 2,957,719 Haistad Oct. 25, 1960 3,012,803I-I afstad g Dec. 12, 1961

1. IN A LATCH MECHANISM FOR LATCHING A DOOR MEMBER MOUNTED FOR OPENINGAND CLOSING MOVEMENTS RELATIVE TO A COOPERATING JAMB MEMBER, AND INWHICH SAID JAMB MEMBER IS PROVIDED WITH A RIGIDLY MOUNTED KEEPERELEMENT, AN IMPROVED FRICTION CATCH, SAID IMPROVED FRICTION CATCHCOMPRISING: (A) A SUPPORTING HOUSING RIGIDLY SECURED TO SAID DOORMEMBER, (B) A PAIR OF ELONGATED COIL SPRINGS CARRIED BY SAID SUPPORTINGHOUSING IN SPACED RELATION TO SAID JAMB MEMBER WITH THE RESPECTIVE ENDPORTIONS OF SAID COIL SPRINGS FIXEDLY DISPOSED WITH RESPECT TO SAID DOORMEMBER, (C) SAID COIL SPRINGS BEING DISPOSED IN GENERAL AXIALPARALLELISM WITH ONE ANOTHER, (D) SAID COIL SPRINGS BEING POSITIONEDRELATIVE TO SAID SUPPORTING HOUSING AN GENERALLY LONGITUDINAL ENGAGEMENTWITH ONE ANOTHER AND FURTHER ARRANGED AND ADAPTED SO THAT ONE OF SAIDSPRINGS IS ENGAGED BY SAID KEEPER ELEMENT DURING INITIAL OPENINGMOVEMENT OF SAID DOOR MEMBER WITH RESPECT TO SAID JAMB MEMBER ANDCONCERTED LATERAL DEFLECTION IS THEREBY IMPARTED TO BOTH OF SAID COILSPRINGS IN THE GENERALLY SAME LATERAL DIRECTION DURING SAID MOVEMENT,